Web indexes not updated upon publish

Question

I am hoping to understand the cause of this and hopefully find a solution - I have looked at every possible solution, but haven't been able to fix it.

Sitecore v8.2 update 3 using SOLR.

In my current set up, Core DB is not shared between CM and CD servers. Index update strategy for web db is onPublishEndAsync.

I created a new item and published it. Item was published to the web db, but the item didn't appear in the index. I thought perhaps core db might have a play in this. So, I changed the settings as follows.

1. Both CM and CD servers to share the core db.
2. Set up the InstanceName and Publishing.PublishingInstance instance name on CM and CD servers. On CM server, the value for these settings is CM. On the CD server, InstanceName is left blank and Publishing.PublishingInstance value is CM
3. Updated the eventqueue polling interval to 1 minute.
4. Changed the crawling log to add debug information.

Index is still not updated and the message that I see in the logs is 'Event Queue is empty. Incremental update returns'

All the events are processed in the event queue according to EventQueueStats.aspx

What could be the cause of it?

Edit:

I kicked off index rebuild from 'developers' tab, but even that didn't update the web index. The core name and the ID is correct.

Job ended: Index Rebuild (sitecore_web_index) (units processed: )

Answer 1

Based on Sitecore Documentation, your Core DB must be shared between CM and CD!

In the standard multiserver Sitecore environment, all the content management and content delivery instances share the Core and Web databases, and all the content management instances share the Master database. This means that you have to use the same connection strings to the databases for the configuration file of each server.

The following diagram illustrates the connections between the servers and the content databases in a standard multiserver Sitecore setup:

Events are delivered from one instance to another as records in EventQueue data table. By default, Sitecore uses Core DB for storing these events, but that can be changed in config.

<eventing defaultProvider="sitecore">
  <providers>
    <clear/>
    <add name="sitecore" type="Sitecore.Eventing.EventProvider, Sitecore.Kernel" systemDatabaseName="core"/>
  </providers>
</eventing>

If shared Core DB is not possible for any reason, set up SQL replication for Core database from CM to CD to synchronize events.

You can find more information regarding SQL replication in Sitecore documentation - SQL Server Replication Guide